This application is the national phase under 35 U.S.C. xc2xa7 371 of PCT International Application No. PCT/SE99/01661 which has an International filing date of Sep. 23, 1999, which designated the United States of America and was published in English.
The present invention relates to a device for quick fitting and insulation of a target for radioisotope production
An isotope production system is a complex system with several subsystems and functions. Such a system produces radioactive tracers, which means that the system has to be in harmony with a number of regulations for such activities, particularly regarding radiation hazards.
Production of radio-isotopes takes place in so called xe2x80x9ctargetsxe2x80x9d which are mounted either directly onto a suitable particle accelerator, normally a cyclotron or on an ion beam transfer line extension from the accelerator.
Targets also need regular maintenance. Time between services depends on operation time, beam current level, type of target, etc. Sudden failures, such as target window ruptures, may also occur. A target window normally constitutes a thin foil of the order 10-25 xcexcm made of, for instance, titanium or an alloy having the corresponding characteristics. Such thin window foils are used to separate a target media space in the target body from the vacuum space of the cyclotron.
The target body will get heated from the irradiation by the ion beam, and therefore has to be cooled. At all instances the user would like to commence their research and clinical program without loosing time. To wait too long for a radioactive target to cool down is not a realistic scenario. A faulty target is desired to be replaced immediately. Therefore, the elapsed time for removal of a target is of great importance, besides to limit the dose exposure to maintenance staff, but the logistics related to the maintenance actions and the design of the target itself are also important.
This implies that mechanical problems arise as the target has to be fixed to, but also releasable from, the vacuum system of an ion beam accelerator system or its ion beam transfer extension line. In the case of an accelerator system there is also a need for a radiation shield, to be able to house the device in a proper environment regarding radiation hazards, which means that normally a lot of restricted space must be reserved. The GE MINItrace, for instance, discloses an integrated device adopted for localised production of short-lived PET (Positron Emission Tomography) isotopes for medical diagnostics for instance at a local hospital. Generally there is then a desire that an operator of the isotope production system should be able to keep a maximum distance to a target which has to be removed during the operation of the facility.
The present invention discloses a target connection and insulation having a quick fitting to a small cyclotron housed in an integrated radiation shield. The target will be easily accessed after opening one of the radiation-shielding doors of the shield and the target device can then be manipulated while still minimising radiation hazards for the operator of the PET isotope production facility.
A device according to the present invention is set forth by the independent claim 1 and further embodiments of the device are defined by the dependent claims.